Chihuahuan Desert visitors often are amazed at the power of the sun here! Sunscreen helps us, but what about plants? Isn't the sun harsh on them, too? Maybe you have never thought of plants getting a sunburn, but that's a real danger. But cacti, in particular, have some amazing adaptations that help them withstand our blazing sun!
Look at a prickly pear cactus. Which way do the pads face, and how are they shaped? The pads are round and flat, and grow so only the narrowest part of the pad faces the sun during the hot part of the day!
Other strategies are used, as well. You may have encountered those
nasty spines. But look—in some cacti, these spines shade the stem so it
doesn't get sunburned! As the sun moves, different parts are in shadow, so no place
on the cactus gets too much exposure. Can you think of other ways plants might protect
themselves? If so, look around. You just might find a plant doing it!
Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.
Contributor: Kodi Jeffery, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
Top: Pricklypear cactus. La Union, Doña Ana Co., NM, 8 Jan 2001. Bottom: A captive cactus showing a heavy sunscreen of "hairs". Photographs by A. H. Harris.